Biofeedback Virtual Reality Sleep Assistant

ABSTRACT

Biofeedback virtual reality sleep assistant technologies monitor one or more physiological parameters while presenting an immersive environment. The presentation of the immersive environment changes over time in response to changes in the values of the physiological parameters. The changes in the presentation of the immersive environment are configured using biofeedback technology and are designed to promote sleep.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of U.S. ProvisionalPatent Application Ser. No. 61/813,037, filed Apr. 17, 2013, which isincorporated herein by this reference.

BACKGROUND

Insomnia is the most common sleep disorder. Insomnia is considered ahyper-arousal disorder in which both cognitive and physiological domainsare over-activated. Research has shown that insomnia is associated withelevated autonomic nervous system activation, particularly at sleeponset that can adversely impact a person's health and well-being in anumber of ways. Sleep onset in insomniacs is characterized by highlevels of cognitive activity, worry, rumination and intrusive thoughtsthat, together with the autonomic hyperactivation, impede the onset ofsleep. Predisposing factors that can increase a person's vulnerabilityto insomnia include age, gender, coping strategy, personality traits,and genetic factors. Insomnia can be triggered by acute stressfulevents, such as illness or trauma; it can be a chronic disorder withoutspecific cause, or can be a symptom of other disorders. Perpetuatingfactors, such as the use of caffeine or alcohol, excessive worry, andirregular wake/sleep schedules, may contribute to the development andpersistence of insomnia.

Cognitive-Behavioral Therapy (CBT) and pharmacotherapy are two mainlines of treatment that are currently available for insomnia. However,many insomnia sufferers do not wish to use pharmacotherapy and there islimited availability of CBT.

BRIEF DESCRIPTION OF THE DRAWINGS

This disclosure is illustrated by way of example and not by way oflimitation in the accompanying figures. The figures may, alone or incombination, illustrate one or more embodiments of the disclosure.Elements illustrated in the figures are not necessarily drawn to scale.Reference labels may be repeated among the figures to indicatecorresponding or analogous elements.

FIG. 1 is a simplified depiction of a person using an embodiment of abiofeedback virtual reality sleep assistant as disclosed herein;

FIG. 2 is a simplified block diagram of at least one embodiment of acomputing environment for the sleep assistant of FIG. 1;

FIG. 3 is a simplified module diagram illustrating an environment of atleast one embodiment of the sleep assistant of FIG. 1 in operation;

FIG. 4 is a simplified flow diagram of at least one embodiment of amethod for promoting sleep with the sleep assistant of FIG. 1;

FIG. 5 is a simplified plot illustrating diaphragmatic breathing atapproximately 6 breaths per minute during use of at least one embodimentof the sleep assistant of FIG. 1 prior to the onset of sleep. In thefigure, breathing data recorded by the Piezoelectric bands and IMUsensor are overlapped to illustrate the reliability of the computingdevice (e.g., a smart phone) in detecting breathing rate under slowbreathing conditions;

FIG. 6 is a simplified plot illustrating normal breathing frequencyduring a period of sleep, immediately following the sleep onset. In thefigure, breathing data recorded by the Piezoelectric bands and IMUsensor are overlapped to illustrate the reliability of the computingdevice (e.g., a smart phone) in detecting breathing rate under normalbreathing conditions; and

FIGS. 7-9 are simplified plots of illustrative test results obtainedduring the use of at least one embodiment of the sleep assistant of FIG.1.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and are described in detailbelow. It should be understood that there is no intent to limit theconcepts of the present disclosure to the particular forms disclosed. Onthe contrary, the intent is to cover all modifications, equivalents, andalternatives consistent with the present disclosure and the appendedclaims.

Insomniacs are characterized by elevated levels of physiological arousal(e.g. high heart rate, elevated high frequency electroencephalographicactivity) together with cognitive hyperactivation (e.g. anxiety, worry,rumination, intrusive thoughts), particularly at sleep onset. Also, formany insomniacs, the bed and bedroom can become associated with adisturbed sleep pattern. As a result, entry into the familiar bedroomenvironment can become a conditioned cue that perpetuates and increasesthe severity of insomnia. As disclosed herein, virtual reality scenarioscan be designed to remove individuals from their undesirable sleepenvironment by immersing them in a new, peaceful and relaxingenvironment, distracting them from other factors that might contributeto insomnia, such as worry and rumination. Additionally, as disclosedherein, biofeedback techniques can be incorporated into a virtualreality system to promote psychophysiological relaxation (by reducingphysiological hyper-arousal) and thus promote their sleep. To do this,some of the disclosed embodiments focus the application of biofeedbackand virtual reality techniques at the point in time that is prior tosleep onset. As used herein, “sleep onset period” generally refers tothe time period beginning with “lights out,” when the person begins theprocess of trying to fall asleep, and continues up to the point of lossof consciousness, e.g., when the person enters the initial sleep state,which usually occurs before the polysomnography (PSG) sleep onset. Aftersleep onset, the techniques disclosed herein can be discontinued becausethe person is no longer conscious of the immersive virtual environment.In other words, some of the disclosed embodiments are directed tohelping people guide themselves across the sleep onset process topromote the transition from the conscious (awake) to the unconsciouslevel (sleep). In this way, aspects of the disclosed embodiments applybiofeedback and virtual reality techniques to make the process offalling asleep easier.

Referring now to FIGS. 1 and 2, an embodiment of a biofeedback virtualreality system 100 includes a virtual reality device 240 and a wearablesensor device 210. The device 210 may be embodied as a mobile computingdevice, as shown in FIG. 1, or as a wearable smart-sensor (e.g. an IMUor inertial measurement unit) that communicates wirelessly with a mobilecomputing device (such as a smart phone lying on a table next to theperson). In other words, the device 210 may include two parts: [1] awearable sensor and [2] a mobile computing device (where the mobilecomputing device is a separate device from the sensor and may interfacewith the sensor by wireless (e.g., by WIFI, BLUETOOTH, or other suitablewireless or optical communication technology), or may include one part(e.g., a mobile computing device with an integrated sensor). The mobilecomputing device and/or the smart-sensor communicates wirelessly withthe virtual reality device 240 (e.g., eye wear and headphones). Thevirtual reality device 240 immerses a person in a virtual realityenvironment 116. The wearable smart sensor together with the mobilecomputing device 210 operates a sleep assistant computer application 218that applies biofeedback technology to the presentation of the immersivevirtual environment 116, in order to target a state of hyper-arousal (orhyper-activation) being experienced by the person using the system 100(“user”). The system 100 creates a positive biofeedback loop in whichthe virtual reality device 240 provides cognitive relaxation/distractionand the biofeedback technology embodied in the sleep assistantapplication 218 promotes sleep by providing positive feedback (bymodulating the degree of immersion in the virtual environment 116) inresponse to physiological signals indicating the user's current level ofrelaxation. Using the biofeedback technology, the system 100 presentsincreasingly immersive virtual reality environments as the user producesthe desired level of physiological activation, and then modulates thevirtual environment so as not to disturb the person once they havefallen asleep. Alternatively or in addition to presenting the immersivevirtual reality environments, the system 100 can control various aspectsof the user's surrounding physical (real-world) environment, in responseto the biofeedback signals. For instance, the system 100 can communicatewith various smart devices in the room, such as devices that provide orreduce ambient lighting, including an alarm clock, shades, and/or otherdevices, to reduce distractions that may be introduced by such devices.For example, the system 100 can use the biofeedback signals (e.g., theuser's breathing rate) to automatically change an aspect of the user'sphysical environment; e.g., if the user slows down his or her breathingrate, the system 100 may decrease the brightness of the room. Theimmersive environment 116 is “virtual” in the sense that it includescomputer-synthesized elements that are presented to the user in place ofor in conjunction with the real-world environment. As used herein,“virtual reality” or “VR” may refer to, among other things, virtualreality, augmented reality, enhanced reality, and/or other types ofinteractive or non-interactive computer-generated immersive userexperiences. For example, in some embodiments, the immersive virtualenvironment 116 may include a visual display 118 that presents a seriesof animated two- or three-dimensional visual elements (e.g., graphicalelements 122, 124, 126, 128) against a relatively static graphicalbackdrop (e.g., element 120), and the person experiences the visualdisplay 118 passively (e.g., by viewing only). In other embodiments, thesystem 100 may allow the user to interact with the elements presented inthe visual display 118 (e.g., via an “avatar” or by the user directlynavigating in the scenario using, for instance, gaze, gestures orpointing devices). For instance, the system 100 may permit the user tomove objects around in the virtual environment, or to interact with orinsert themselves into the virtual environment as an avatar. As anexample, a “sleep mask” configured as a virtual reality device 240 candetect the user's gaze and move the avatar in the same direction as theuser's gaze allowing the user to navigate in the virtual environmentmoving his eyes. As another example, the system 100 may change the pointof view or focus, or zoom in or zoom out in a particular direction, inresponse to the user's gestures or other body movements, or may rotate,pan, or otherwise adjust the virtual scene in response to acharacteristic of the person's gaze (e.g., gaze direction, pupildilation, etc.), or in response to other detected bio-signals (e.g.,reduction in muscle activity). Using the bio-feedback mechanism, theuser is an active participant in controlling the virtual environment andsynthesized sounds. In general, a greater physiological relaxation (aspromoted by the sleep assistant 218) leads to a more pleasantenvironment (e.g., increased immersion in the virtual reality) and thuspromotes more cognitive relaxation/distraction. The sleep assistant 218responds to increased physiological relaxation (as detected by, e.g., areduction in breathing rate) by increasing the degree of virtualimmersion (by providing, for example, pleasant/relaxing sounds, morevisual elements in the immersive environment that increase the user's“sense of presence” in the immersive environment), etc. The increaseddegree of virtual immersion then leads to even greater cognitiverelaxation/distraction (e.g. the person is now fully immersed in avirtual environment and he/she forgot all worries, ruminations, etc.),which promotes sleep.

The virtual environment 116 is immersive in the sense that it isdesigned to attract the user's attention by increasing the user's senseof presence in a virtual world and by removing distractions that mayoccur in the surrounding real-world scene, e.g., by occluding thebackground and/or restricting the user's peripheral vision. The system100 may achieve the immersive nature of the virtual environment 116 bypresenting the visual display 118, playing an audio soundtrack 130,presenting a combination of the visual display 118 and the audiosoundtrack 130, and/or providing other sensory stimuli. In allembodiments, the level of brightness of the visual stimulation providedby the visual display 118 is low, in order to avoid any alterations inhormone production (e.g. to avoid changes in melatonin).

The illustrative immersive virtual environment 116 includes acombination of visual 118 and audio 130 stimuli, but other embodimentsmay include other types of sensory stimuli, such as tactile,temperature, taste, smell, and others, alternatively or in addition tothe visual 118 and audio 130 stimuli. For example, some embodiments ofthe virtual environment 116 only include visual stimuli while otherembodiments only include audio stimuli. The system 100 coordinates thepresentation of the various sensory stimuli with physiologicalinformation in real time to create a state of relaxation in the personexperiencing the immersive virtual environment 116. For example, asexplained further below, the system 100 may increase or decrease any ofa number of features of any of the sensory stimuli, or selectively turndifferent sensory stimuli on and off, over time in response to changesin the person's physiological parameters. As used herein, “in real time”may refer to, among other things, the fact that an automated biofeedbackprocess occurs in response to sensed physiological information about theperson using the system 100, during a period in which the person isusing the system 100. In other words, the illustrative system 100changes one or more aspects of the immersive virtual environment 116directly in response to changes in the sensed physiological information,using biofeedback technology based on user actions that is designed topromote sleep. To do this, the mobile/wearable computing device 210and/or the virtual reality device 240 analyze one or more physiologicalparameters that are obtained or derived from sensor signals. As usedherein, “physiological parameters” may refer to, among other things,breathing rate (respiration rate) (e.g., breaths per minute), heart rate(e.g., beats per minute), brain activity (e.g. electroencephalographicsignals), body movements, muscle activity; or any other type ofmeasurable human physiological activity, or any combination of theforegoing. Using biofeedback technology, the system 100 modifies theimmersive virtual environment 116 in response to changes in thephysiological parameters in a manner that is designed to guide theperson away from the state of hyper-arousal and toward a state of sleep.

Different physiological parameters may have different roles in modifyingthe various aspects of the virtual environment (e.g., breathing rate canguide the speed of the navigation in the virtual environment whereas themuscle tone may guide the density of the virtual elements presented inthe immersive environment 116). As an example, if the user decreases hisor her breathing rate, the system 100 can reduce the speed of the fishswimming in an aquatic scene (but not change other aspects of theenvironment 116); and if, at the same time, the user reduces his or hermuscle activity, the system 100 can increase the number of fish swimmingin the visual scene. Thus, different physiological parameters can belinked with different aspects of the immersive scenario 116 usingfeedback on different bio-signals, in order to potentially increase theuser's relaxation.

Referring now to FIG. 1 in more detail, the illustrative visual display118 is embodied as a three-dimensional (3D) display of visual elements.In the illustration, the visual elements depict an aquatic scene andinclude a background 120 (e.g., water), a background element 128 (e.g.,coral), and a number of foreground elements 122 (e.g., fish), 124 (airbubbles), 126 (e.g., rocks). The system 100 can adjust the presentationof any of the visual elements 120, 122, 124, 126, 128, or add or removevisual elements, in response to changes in physiological parameters.Further, each of the visual elements has a number of features, includingspeed (e.g., the rate at which the element moves across the display),quantity (e.g., the number of elements of a certain type presented onthe display), density (e.g., the number of elements presented in acertain area of the display), frequency (e.g., the rate at whichelements of a certain type are presented), color, brightness, contrast,direction of movement, depth (in 3D), focus (e.g. clarity), point ofview, and/or complexity (e.g., amount of finer-grain details depicted inthe element). The system 100 can modify any of these and/or otherfeatures of the visual elements depicted in the visual display 118,based on the user's physiological parameters. Of course, while thevisual display 118 depicts an aquatic scene, any type of visual displaythat is designed or selected to promote sleep may be used. For example,an ocean, sky, or forest scene may be used, or the visual display 118may be configured according to the preferences of a particular user ofthe system 100. In FIG. 1, it should be understood that in operation,the visual display 118 is actually displayed in the virtual realityviewing glasses 112, but is shown as projected in order to betterillustrate the details described above.

The illustrative audio soundtrack 130 includes a number of audioelements, which may include various types of sounds (e.g., spoken words,music, nature sounds, etc.) or a combination thereof. In theillustration, the audio elements are sounds that are coordinated withthe visual display 118 (e.g., water flowing and bubbling sounds);however, the audio soundtrack can include any type of audio selected orconfigured to promote sleep, including selections from the user'sdigital music library. The system 100 can adjust the presentation of anyof the audio elements, or add or remove audio elements, in response tochanges in physiological parameters. Each of the audio elements has anumber of features, including volume, content (e.g., words, sounds,and/or music), speed (e.g., tempo), complexity (e.g., number ofdifferent types or layers of sound), degree of “surround sound,” and/orintensity (e.g., acoustic intensity). The system 100 can modify any ofthese and/or other features of the audio elements 130 based on theuser's physiological parameters.

The illustrative wearable smart-sensor and mobile computing device 210includes a computing device 110 (e.g., a smartphone, a tablet computer,an attachable/detachable electronic device such as a clip-on device, asmart watch, smart glasses, a smart wristband, smart jewelry, and/orsmart apparel) and a positioner 132 (e.g., a strap, tether, clip,VELCRO® tab, etc.). However, any type of computing device that includesa processor and memory and can interact with the virtual reality device240 in a relatively non-intrusive manner (e.g., without causingdiscomfort to the person using the system 100) may be used as thecomputing device 110.

The positioner 132 is configured to secure the mobile or wearablecomputing device 210 in a position in which a sensor 232 (FIG. 2) of thedevice 210 can detect the user's physiological activity and generatephysiological signals representing the user's physiological activity.However, the positioner 132 may be omitted, in some embodiments.Additionally, the sensors used to detect the user's physiologicalactivity do not need to be attached to or worn by the person. Forexample, the physiological sensor 232 can be incorporated in theperson's bed or mattress, or into a mattress pad or bed linens (e.g., afitted sheet). Additional details of the mobile or wearable computingdevice 210 are described below with reference to FIG. 2.

The illustrative virtual reality device 240 includes a visual displaysystem 112 and an audio delivery system 114. The illustrative visualdisplay system 112 is embodied as commercially available virtual realityeyewear. Other embodiments of the visual display system 112 utilizeother types of visual display systems, such as high-definition videoglasses, non-rigid sleep masks adapted for virtual reality, televisions,projection systems (to project a display of visual elements onto a wallor ceiling), or holograms.

The illustrative audio delivery system 114 is embodied as commerciallyavailable bone-conducting headphones. Other embodiments of the audiodelivery system 114 use other methods of audio delivery, such asconventional audio headphones (e.g., earbuds), three-dimensional (3D)surround sound systems, remote speakers, indoor waterfall systems orfountains, and/or other electronically-controllable noise-makingdevices. In general, the components of the system 100 are incommunication with each other as needed by suitable hardware and/orsoftware-based communication mechanisms, which may be enabled by anapplication programming interface, operating system components, anetwork communication subsystem, and/or other components. Additionaldetails of the virtual reality device 240 are described below withreference to FIG. 2.

Referring now to FIG. 2, a simplified block diagram of an exemplarycomputing environment 200 for the computing system 100 is shown. Theillustrative environment 200 includes the mobile or wearable computingdevice 210 and the virtual reality device 240, which are incommunication with one or more smart devices 266 and/or one or moreserver computing devices 280 via one or more networks 264. Thebiofeedback VR sleep assistant 218 is, illustratively, embodied as adistributed application including “front end” components that are localto each of the devices 210, 240, 270 and including “back end” portionsthat reside on the server(s) 280 (e.g., “in the cloud”). Similarly, alibrary or searchable database of selectable immersive virtualenvironments 116 may be distributed across the network 270. For example,the immersive virtual environments 222, 252, 292 may include a number ofdifferent virtual environments 116, or copies or portions of particularvirtual environments 116. Further, other portions of the system 100 maybe distributed on various devices 210, 240, 280 across the network 270,such as mapping functions 234. In other embodiments, however, the sleepassistant 218, the mapping function(s) 234, and the immersive virtualenvironment(s) 222, 252, 292 may be stored entirely on the mobile orwearable computing device 210 or entirely on the virtual reality device240. In some embodiments, portions of the sleep assistant 218, themapping function(s) 234 or the immersive virtual environment(s) 222,252, 292 may be incorporated into other systems or interactive softwareapplications. Such applications or systems may include, for example,operating systems, middleware or framework (e.g., applicationprogramming interface or API) software, and/or user-level applicationssoftware.

The mobile or wearable computing device 210 may be embodied as any typeof computing device that is capable of performing the functionsdescribed herein (e.g., modulating the presentation of the immersivevirtual environment 116 based on physiological signals). In someembodiments, the devices 210, 240 may be integrated as a unitary device.Such a unitary device may also include one or more physiological sensors232, 262.

The illustrative mobile or wearable computing device 210 includes atleast one processor 212 (e.g. a controller, microprocessor,microcontroller, digital signal processor, etc.), memory 214, and aninput/output (I/O) subsystem 216. Although not specifically shown,embodiments of the processor 212 may include separate baseband andapplications processors. Features of the baseband and applicationsprocessors may be located on the same or different hardware devices(e.g., a common substrate). The baseband processor interfaces with othercomponents of the mobile or wearable computing device 210 and/orexternal components to provide, among other things, wirelesscommunication services, such as cellular, BLUETOOTH, WLAN, and/or othercommunication services. In general, the applications processor handlesprocessing required by software and firmware applications running on themobile or wearable computing device 210, as well as interfacing withvarious sensors and/or other system resources. However, it should beunderstood that features typically handled by the baseband processor maybe handled by the applications processor and vice versa, in someembodiments.

Although not specifically shown, it should be understood that the I/Osubsystem 216 typically includes, among other things, an I/O controller,a memory controller, and one or more I/O ports. The processor 212 andthe I/O subsystem 216 are communicatively coupled to the memory 214. Thememory 214 may be embodied as any type of suitable computer memorydevice (e.g., volatile memory such as various forms of random accessmemory).

The I/O subsystem 216 is communicatively coupled to a number ofcomponents, including a user interface subsystem 224. The user interfacesubsystem 224 includes one or more user input devices (e.g., amicrophone, a touchscreen, keyboard, virtual keypad, etc.) and one ormore output devices (e.g., audio speakers, displays, LEDs, etc.). TheI/O subsystem 216 is also communicatively coupled to a data storagedevice 220, a communications subsystem 230, and the physiologicalsensor(s) 232, as well as the biofeedback VR sleep assistant 218. Thedata storage device 220 may include one or more hard drives or othersuitable persistent data storage devices (e.g., flash memory, memorycards, memory sticks, and/or others). The physiological sensing devices232 may include motion sensors, pressure sensors, kinetic sensors,temperature sensors, biometric sensors, and/or others, and may beintegrated with or in communication with the mobile or wearablecomputing device 210. For example, the sensing device 232 may beembodied as an inertial measurement unit (IMU) sensor of the mobile orwearable computing device 210, and as such may include a multiple-axisgyroscope and a multiple-axis accelerometer. In some embodiments, arespiratory effort sensor, such as a piezo sensor band or a respiratorytransducer, may be in communication with or embodied in the computingdevice 210, alternatively or in addition to the IMU.

Portions of the sleep assistant 218, the mapping function(s) 234, andthe immersive virtual environment(s) 222 reside at least temporarily inthe data storage device 220. For example, the virtual environments 222may include a subset of the library of virtual environments 292, wherethe subset 222 has been selected by the user or provided as part of abase configuration of the sleep assistant 218 or the computing device210. Portions of the sleep assistant 218, the mapping function(s) 234,and the immersive virtual environment(s) 222 may be copied to the memory214 during operation of the mobile or wearable computing device 210, forfaster processing or other reasons.

The communication subsystem 230 may communicatively couple the mobile orwearable computing device 210 to other computing devices and/or systemsby, for example, a cellular network, a local area network, wide areanetwork (e.g., Wi-Fi), personal cloud, virtual personal network (e.g.,VPN), enterprise cloud, public cloud, Ethernet, and/or public networksuch as the Internet. The communication subsystem 230 may, alternativelyor in addition, enable shorter-range wireless communications between themobile or wearable computing device 210 and other computing devices(such as the virtual reality device 240), using, for example, BLUETOOTHand/or Near Field Communication (NFC) technology. Accordingly, thecommunication subsystem 230 may include one or more optical, wiredand/or wireless network interface subsystems, cards, adapters, or otherdevices, as may be needed pursuant to the specifications and/or designof the particular mobile or wearable computing device 210. Additionally,the communication subsystem 230 may include a telephony subsystem, whichenables the computing device to provide telecommunications services(e.g., via the baseband processor). The telephony subsystem generallyincludes a longer-range wireless transceiver, such as a radio frequency(RF) transceiver, and other associated hardware (e.g., amplifiers,etc.).

The user interface subsystem 224 includes an audio subsystem 226 and avisual subsystem 228. The audio subsystem 226 may include, for example,an audio CODEC, one or more microphones, and one or more speakers andheadphone jacks. The visual subsystem 228 may include, for example,personal viewing glasses, projection devices, holograms, televisions,liquid crystal display (LCD) screens, light emitting diode (LED)screens, or other visual display devices. The one or more physiologicalsensor(s) 232 initially detect the user's “baseline” physiologicalparameters (e.g., the user's actual measured parameters at the beginningof a sleep promotion session). Once the user's baseline condition or“physiological status” is established, the system 100 presents aninitial immersive virtual environment 116 and enters “feedback mode,” inwhich the sensor(s) 232 periodically detect the physiological responsesof the user to the presented immersive virtual environment 116, andprovide the sleep assistant 218 with physiological signals that can beused by the sleep assistant 218 to determine the user's state ofrelaxation as it changes over time. The physiological signals output bythe sensor(s) 232 may include signals that represent respiration rate,heart rate, brain activity (e.g. electroencephalogram (EEG)), bodytemperature, and/or other physiological parameters. For example, thesensor 232 may be embodied as an IMU built into the computing device 210or the virtual reality device 240, which is used to measure the user'sbreathing rate by detecting the rise and fall of the user's chest orabdomen over time during normal respiration.

In other embodiments, the physiological sensor 232 can includemeasurement tools that are external to the computing device 210 butwhich are in communication with the device 210. An example of anexternal physiological sensor 232 is “textile electrodes,” which areformed by knitting or weaving conductive fibers into apparel orgarments. Textile electrodes can pick up signals from the heart andother muscles. The physiological activity sensed by the textileelectrodes are transmitted through the conductive fibers that are woveninto the garment to a processing unit, which then passes the receivedsignals to the mobile or wearable computing device 210, generallythrough a wireless data connection.

Referring now to the virtual reality device 240 of FIG. 2, the virtualreality device 240 may be embodied as any type of device that is capableof performing the functions described herein (e.g., presenting theimmersive virtual environment 116 to the user). To do this, theillustrative virtual reality device 240 is equipped with an audiosubsystem 256 and a visual subsystem 258, which may be embodiedsimilarly to the audio subsystem 226 and the visual subsystem 228described above. Accordingly, the virtual reality device 240 may beembodied with components similar to those of the mobile or wearablecomputing device 210. For example, in some embodiments, the virtualreality device 240 has a processor 242, memory 244, and an I/O subsystem246 similar to the mobile or wearable computing device 210. In general,elements of the virtual reality device 240 having the same or similarname as elements of the mobile or wearable computing device 210 may beembodied similarly, and description of those elements is not repeatedhere. While not specifically shown in FIG. 2, it should be understoodthat the virtual reality device 240 may include other components asneeded to control or provide other various forms of sensory stimuli,such as an ambient temperature controller subsystem, an aroma subsystem,and/or an air movement subsystem. In some embodiments, the virtualreality device 240 is comprised of separate devices. For example,wearable personal viewing glasses and headphone ear buds may be separatecomponents of the virtual reality device 240, or may be integrated intoa single device (e.g., GLASS by Google, Inc. or a similar device).

Referring now to the smart device(s) 266 of FIG. 2, the smart device(s)266 may be embodied as any type of electronic device capable ofperforming the functions described herein (e.g., controlling an aspectof the user's physical environment). For example, the smart device(s)266 may include smart lighting, heating, cooling, sound, and/orentertainment systems. The smart device(s) 266 may include componentssimilar to those described above, or may simply include controlcircuitry to process control signals received from the sleep assistant218 and adjust a parameter of the device 266 (e.g., light intensity,room temperature, sound volume, etc.). Elements of the smart device(s)266 having the same or similar name as elements of the mobile orwearable computing device 210 may be embodied in a similar manner andaccording to the requirements of the particular smart device 266. Assuch, the description of the similar elements is not repeated here. Inthe illustrative smart device 266, the virtual sleep assistant 218 iscommunicatively coupled to I/O subsystem 276, data storage 274, userinterface subsystem 276, and communication subsystem 278. Data storage274 is used to store portions of the mapping function(s) 234 and theimmersive virtual environment(s) 292.

Referring now to the server(s) 280 of FIG. 2, the server(s) 280 may beembodied as any type of computing device capable of performing thefunctions described herein (e.g., storing portions of the immersivevirtual environments 292 and/or executing portions of the sleepassistant 218). For example, the server(s) 280 may include componentssimilar to those described above. Elements of the server 280 having thesame or similar name as elements of the mobile or wearable computingdevice 210 may be embodied in a similar manner and according to therequirements of the server 280. As such, the description of the similarelements is not repeated here. In the illustrative server 280, thevirtual sleep assistant 218 is communicatively coupled to I/O subsystem286, data storage 290, user interface subsystem 294, and communicationsubsystem 296. Data storage 290 is used to store portions of the mappingfunction(s) 234 and the immersive virtual environment(s) 292.

The computing environment 200 may include other components,sub-components, and devices not illustrated in FIG. 2 for clarity of thedescription. In general, the components of the environment 200 arecommunicatively coupled as shown in FIG. 2 by electronic signal paths,which may be embodied as any type of wired or wireless signal pathscapable of facilitating communication between the respective devices andcomponents.

Referring now to FIG. 3, the biofeedback VR sleep assistant 218 is shownin more detail, in the context of an environment 300 that may be createdduring the operation of the computing system 100 (e.g., an execution or“runtime” environment). As noted above, the sleep assistant 218 isembodied as a computer application. As used herein, “application” or“computer application” may refer to, among other things, any type ofcomputer program or group of computer programs, whether implemented insoftware, hardware, or a combination thereof, and includes operatingsystem programs, middleware (e.g., APIs, runtime libraries, utilities,etc.), self-contained software applications, or a combination of any ofthe foregoing. The sleep assistant 218 is embodied as a number ofcomputerized modules and data structures including a physiologicalsignal acquisition module 312, a physiological signal processing module314, a physiological parameter mapping module 316, an immersiveenvironment control module 318, a data store including a number ofimmersive virtual environments 222, and a learning module 338.

The physiological signal acquisition module 312 receives sensor signals328 from the physiological sensor(s) 232, 262 from time to time duringoperation of the computing device 210 at a specified sampling rate,which may correspond to a sampling rate performed by the computingdevice 210. As described above, portions of the sensor signals 328 mayreflect human body movements that are indicative of the user'sbreathing, heartbeat, or other physiological activity. The signalacquisition module 312 performs standard signal processing techniques(e.g., analog-to-digital conversion, filtering, etc.) to extract theuseful information (e.g., measurements of breathing or heart beatactivity, brain activity or body temperature) from the sensor signals328 and outputs the resulting physiological signals 330. In someembodiments, the signal acquisition module 312 is a standard componentthat is built into the computing device 210. However, the physiologicalsignal acquisition module 312 can also be part of a unit that isexternal to the computing device 210. For instance, the physiologicalsignal acquisition module 312 can be part of the virtual reality device240. The physiological signal acquisition module 312 can becommunicatively coupled to either the visual subsystem 256 or the audiosubsystem 258, in some embodiments. For example, the physiologicalsignal acquisition module 312 may be embodied as a processor incommunication with a heart rate monitor that is built into audioearbuds. As another example, the physiological signal acquisition module312 may be a thermal imager that is remotely placed (with respect to thecomputing device 210) to periodically measure the body temperature ofthe user.

The physiological signal processing module 314 receives thephysiological signals 330 from the physiological signal acquisitionmodule 312, maps the physiological signals to one or more physiologicalparameters (e.g., respiration rate, heart rate, etc.), each of which hasa range of possible values, and calculates the current data value 332for each of the physiological parameters. For example, the physiologicalsignal processing module 314 may determine a value of a physiologicalparameter from one or multiple physiological signals 330, or from one ormultiple instances of the same physiological signal 330 over time. Themodule 314 may execute one or more algorithms to map the physiologicalsignals 330 to physiological parameters or to determine physiologicalparameter values 332. For example, a robust algorithm based on Fourieranalysis may be used to compute the dominant oscillation period from theraw IMU data that is directly related to breathing rate.

The physiological parameter mapping module 316 uses the physiologicalparameter values 332 to determine the immersive virtual environment 116that is to be presented to the user. The physiological parameter mappingmodule 316 maps the physiological parameter values 332 received from thephysiological signal processing module 314 to the features of theimmersive virtual environment 116. For example, if the immersive virtualenvironment 116 includes audio and visual stimuli, the physiologicalparameter value and its mapping determine the features of the audio andvisual stimuli to be presented to the user. In some embodiments, themapping is accomplished by one or more look-up tables that indicaterelationships between various physiological parameter values andfeatures of the immersive virtual environment 116. For instance, alook-up table may link a physiological parameter value or range ofvalues to a pre-determined audio volume and number or type of visualelements to display. In other embodiments, a continuous function (e.g.,a linear or Gaussian function) may be used to define the mapping.Illustrative examples of mapping tables are shown below in TABLE 1 andTABLE 2.

In some cases, a single physiological parameter value of a singleparameter may be used to determine all of the parts of the virtualenvironment 116 to be presented by the user, for example, both thevisual elements and the audio elements. However, the mapping may bedefined differently or determined separately for different elements ofthe virtual environment. For example, a mapping table or mappingfunction 234 may define relationships between respiration rates andfeatures of the visual display 118, while another mapping table ormapping function 234 may define relationships between the respirationrates and features of the audio soundtrack 130. In other cases, multiplephysiological parameters and their corresponding parameter values may beused. For example, one physiological parameter may be used to controlthe visual display 118 and a different physiological parameter may beused to control the audio 130 of other aspects of the two subsystems.Additionally, different mapping tables or functions 234 may be used tocontrol the smart device(s) 266.

In some embodiments, the mapping table or mapping function used by theparameter mapping module 316 may be customized for a particular userbased on user customization data 344. The user customization data 344may include, for example, user preferences, demographic information, orclinical sleep information specific to the user. As an example, thesystem 100 may include a number of different parameter mapping tablesfor different populations of users, and the user customization data 344may be used to select an appropriate mapping table (based on, e.g., age,gender, or body size). The mapping tables or mapping functions, orportions thereof, may be stored in data storage of any of the devices210, 2430, 266, 280, as mapping functions 234, or in other data storagelocations.

With the parameter input value(s) 332 and the mapping table or functionof the parameter mapping module 316, the system 100 determines changesor adjustments to be made to the immersive virtual environment 116 inresponse to the current parameter value(s) 332. For example, theimmersive virtual environment 116 may include a succession of stages,where each stage represents a particular combination of sensory stimuli,and the change or adjustment may include transitioning the presentationto a different stage of the virtual environment 116. The specificationsfor these changes or adjustments are passed to the immersive environmentcontrol module 318 as environment adjustments 334.

In some embodiments, the parameter values 332, corresponding environmentadjustments 334, and subsequent parameter values 332 (e.g., arepresentation of the user's response to the previous environmentadjustment 334) (which may be collectively referred to as “trainingdata”) are passed to the learning module 338 from time to time. Thelearning module 338 applies one or more artificial intelligencetechniques (such as an unsupervised machine learning algorithm) to thetraining data to algorithmically learn the user's typical responses todifferent environment adjustments 334. Based on this learning, thelearning module 338 formulates recommended mapping adjustments 336,which indicate modifications to the mapping function that are based onthe user's actual behavior over time. The learning module 338 passes themapping adjustments 336 to the parameter mapping module 316, whichupdates its mapping table or mapping function based to incorporate themapping adjustments 336.

In some embodiments, the learning module 338 monitors the physiologicalsignals over the course of a sleep session (e.g., overnight) and outputsfeedback (e.g., in the morning) about sleep quality or overall cardiacfunctioning of the user. Alternatively or in addition, the learningmodule 338 can make modifications in the selection of the immersivescenario and/or the degree of immersion in subsequent sleep sessions(e.g., for the following night), in response to its assessments of theuser's previous sleep quality and/or nocturnal physiology. In this way,the system 100 can, in an automated fashion, learn and change theimmersion scenario or settings based on data indicating sleep patternsof a general population (and/or based on a user's individual nocturnalphysiology—e.g., cardiac functioning).

The immersive environment control module 318 controls the modificationsto the presentation of the immersive virtual environment 116 in responseto the physiological signals 330. The immersive environment controlmodule 318 receives the environment adjustments 334, accesses therequisite elements of the immersive environment(s) 222 (which,illustratively, include audio elements 340 and visual elements 342), andconstructs a modified version of the virtual environment 116,incorporating the environment adjustments 334. Where the virtualenvironment 116 includes multiple different types of sensory stimuli,the control module 318 includes a modulator 320, 322, 324, 326 for eachdifferent type of stimulus. For example, the audio modulator 320controls the modification of the presentation of audio elements andtheir respective features (e.g., volume, content, speed, complexity,intensity, and/or other aspects of the audio soundtrack 130), while thevisual scene modulator 322 controls the modification of the presentationof visual elements and their respective features (e.g., objectmovements, number and type of different objects displayed, colorschemes, brightness levels, and/or other aspects of the visual display118). The tactile modulator 324 and the temperature modulator 326operate in a similar fashion to control tactile and temperature stimuli,and similar modulators operate similarly for other types of sensorystimuli. In this way, the illustrative immersive environment controlmodule 318 constructs and adjusts the virtual environment 116 “on thefly,” e.g., by performing graphics rendering in real time, as opposed tosimply selecting and presenting previously created content. Theimmersive environment control module 318 transmits control signals tothe virtual reality device 240 to cause the virtual reality device 240to present the various adjustments to the virtual environment 116 to theuser.

Referring now to FIG. 4, a flow diagram provides an illustration of amethod 400 by which embodiments of system 100 may be used to, forexample, conduct a sleep promotion session. The method 400 may beembodied as computerized programs, routines, logic and/or instructionsthat are executed by the computing system, e.g., the computing device210 and/or the virtual reality device 240. In FIG. 4, a personattempting to fall asleep, or simply to become more relaxed, uses thesystem 100 to immerse themselves in a virtual reality environment. Forexample, the person may be instructed or coached by the sleep assistant218 to slow his or her breathing rate (or may do so on his or her own)in order to cause the virtual reality environment to become moreimmersive. In the method 400, a process of presenting an immersivevirtual environment that adjusts automatically in response to sensorsignals representing physiological activity of the user is performed. Ofcourse, as discussed above, aspects of the user's physical environment(e.g., ambient lighting) can also be adjusted (e.g., by the system 100interfacing with one or more “smart” devices 266 in the physicalenvironment). Such adjustments to the physical environment may beinitiated in conjunction with or separately from the adjustments to thevirtual environment. For example, the system 100 may include one or moreseparate mapping functions 234 that the sleep assistant 218 may use todetermine adjustments to be made to the physical environment in responseto the user's physiological activity.

At block 410, the system 100 selects a virtual environment to bepresented by the virtual reality device 240. As noted earlier, there aremany different types of virtual environments that can be presented; forexample, aquatic scenes (e.g., aquarium or ocean), general naturescenes, or other environments that are designed to promote sleep. Thesystem 100 can select a specific virtual environment in response to userinput, as a result of default settings of the virtual sleep assistant218, or by accessing user customization data 344 (such as a user profileor preferences). Once the virtual environment is selected, the system100 presents an initial stage of the virtual environment until asufficient amount of biofeedback information is received to allow thesystem 100 to begin making dynamic adjustments to the virtualenvironment.

At block 412, the system 100 receives physiological signals output bythe physiological sensor(s) 232, 262, which represent physiologicalactivity of a person using the system 100. At block 414, the system 100processes the physiological signals received at block 412 and determinesone or more physiological parameters and the current parameter values(e.g., breathing rate: 10 breaths per minute) as of the samplinginstance. The parameter values can be calculated or estimated (e.g.,based on a number of breaths detected in a given time interval). Theparameter values can be determined by, for example, acomputer-processing unit of the mobile or wearable computing device 210,or in computer processing units located directly in the physiologicalsensor(s) 232, 262. At block 416, the system 100 determines a stage ofthe immersive virtual environment to present, based on the currentparameter values. In an illustrative embodiment, the process at block416 includes a mapping function in a form of a look-up table that mapsphysiological parameter values to stages of the virtual environment. Asshown in TABLE 1 below, each immersive virtual environment can bedivided into a number of successive stages that can be presented to theuser. Each stage relates to a physiological parameter value or a rangeof physiological parameter values. That is, where a physiologicalparameter has a range of possible values, each stage of the virtualenvironment relates to a different subset of the range of possiblevalues. TABLE 1 illustrates the relationship between a few exemplaryvisual and audio features of an immersive virtual environment and anexemplary physiological parameter.

TABLE 1 Physiological Parameter Mapping - Respiration Rate VISUALFEATURES PHYSIOLOGICAL AUDIO Number of Densities of PARAMETER FEATURESPrimary Speed of Secondary Respiration Rate Audio Foreground ObjectForeground STAGE (bpm) Gains Elements Movement Elements 4 6 0.9 13 0.080.04/0.03/0.03 3 8 0.2 08 1.2 0.02/0.02/0.02 2 12 0.03 05 1.70.02/0.01/0.01 1 16 0.003 01 2.3  0.01/0.007/0.006

In the example of TABLE 1, a single physiological parameter (respirationrate) is mapped to both visual and audio elements of an immersivevirtual environment. Each value of the physiological parametercorresponds to a different stage of the immersive virtual environment,and each stage of the immersive virtual environment relates to audio andvisual features that have different values. The illustrative audiofeature is gain (e.g., volume) and the illustrative visual features arethe number of primary foreground elements (e.g., fish in the example ofFIG. 1), the speed of object movement (e.g., the speed at which the fishtravel across the display), and the densities of secondary foregroundelements (e.g., the density of the bubbles of FIG. 1). In general, lowrespiration rate promotes heart rate variability and, consequently,decreases heart rate. Heart rate variability has been found tosignificantly increase at a respiratory frequency of 6 breaths perminute. Inducing low levels of physiological activity (e.g. loweringheart rate voluntarily via paced breathing) across the sleep onsetprocess helps the system 100 to reduce the elevated level ofpsychophysiological activity (which is typical in insomnia or othercondition involving elevated stress and anxiety)) at the beginning ofthe sleep session and helps the individual fall asleep. In sleepresearch, 6 breaths per minute corresponds to a target breathing ratefor obtaining maximum relaxation. Thus, in TABLE 1, the higher breathingrates correspond to earlier stages in the succession of virtualenvironment stages, and lower breathing rates correspond to laterstages. According to the example of TABLE 1, the virtual environmentbecomes more immersive (presenting a higher number of primary foregroundelements, a higher density of secondary foreground elements, and louderaudio, as the respiration rate decreases. However, the speed of movementof the displayed objects becomes slower as the respiration ratedecreases. Using a mapping such as illustrated by TABLE 1 enables thesystem 100 to gradually present a more immersive experience if the userincreases his or her relaxation and reacts favorably to thepreviously-presented stage of the virtual environment. In theillustrated embodiments, the system 100 increases the degree of virtualimmersion in response to reductions in the user's respiration rate. Oncethe user's respiration has decreased, the system 100 can makeadjustments to the immersive virtual environment 116 based on othercriteria, such as the previously-presented stages of the immersivevirtual environment 116 (e.g., adjust the quantity or speed of visualfeatures based on the quantity or speed of the visual features presentedin the previous stage).

In TABLE 2 below, an illustrative example of a mapping function relatingto the use of muscle activity as primary feedback parameter is shown. Asdiscussed above, system 100 can adjust the immersive virtual environment116 (and/or an aspect of user's physical environment) in response to thedetection of the user's muscle activity. For example, two electromyogram(EMG) sensors can be incorporated in a “sleep mask” to detect the muscleactivity of corrugator supercilii muscle (by detecting the electricalpotential generated by muscle bundles). The resting EMG tone may berecorded for a short time (e.g. 1 min) when the user is lying down inbed maintaining their neutral “position,” to determine the baseline EMGtone (μv). The individual may then be instructed or coached by the sleepassistant 218 to decrease his or her level of “muscle contraction” inhis or her facial muscles, and particularly in the forehead (or, ofcourse, the user may do so on his or her own, without coaching). Thestages of immersion in the virtual environment 116 may increase based onthe percentage decrease in muscle contraction from the baseline levels.

TABLE 2 Physiological Parameter Mapping - Muscle Activity. PHYSIOLOGICALVISUAL FEATURES PARAMETER AUDIO Number of Densities of Muscle Tone (%FEATURES Primary Speed of Secondary changes respect to Audio ForegroundObject Foreground STAGE baseline levels) Gains Elements MovementElements 4 −60 0.9 13 0.08 0.04/0.03/0.03 3 −30 0.2 08 1.20.02/0.02/0.02 2 −10 0.03 05 1.7 0.02/0.01/0.01 1 Individuals' baseline0.003 01 2.3  0.01/0.007/0.006 levels (in μV)

Of course, the mechanics of each stage of the immersive virtualenvironment are not limited to types of features and mappings shown inTABLE 1 and TABLE 2 or the data values shown in TABLE 1 and TABLE 2.Other strategies for dynamically changing the immersive virtualenvironment to induce sleep are within the scope of this disclosure.

At block 418, the immersive virtual environment is presented using thevirtual reality device 240. To do this, the system 100 constructs theappropriate stage of the immersive virtual environment and transmits thestage content and control commands to the virtual reality device 240.Once received, the virtual reality device 240 executes the commands topresenting the virtual environment. In some embodiments, portions of thestage content (e.g., the visual elements and/or audio elements) may bestored in the virtual reality device 240, such that the system 100 onlytransmits control commands to the device 240.

To accomplish dynamic changes in the virtual environment, the system 100processes frequent physiological feedback data from the sensors 232,262. For example, the system 100 may process the physiological data at afrequency that corresponds to the internal sampling rate of thecomputing device 210 (e.g., 100 Hz for a standard smart phone). At block420, the system 100 receives new physiological signals that are detectedsubsequent to the presentation of the stage of the virtual environmentat block 418. At block 422, new physiological parameter values arecalculated from the new physiological signals received at block 420.

The system 100 considers whether to continue the biofeedback virtualreality sleep promotion at block 424. If it is determined that thevirtual reality sleep promotion is to be discontinued, then the method400 concludes at block 428 and the system 100 discontinues thepresentation of the virtual environment. In some embodiments, thevirtual reality sleep promotion is discontinued by a timer set to turnthe sleep assistant 218 off after sleep promotion has been running for acertain period of time. In other embodiments, the virtual reality sleeppromotion may be stopped due to an input from a user. In still otherembodiments, the system 100 determines a sleep state based on thephysiological signals or using a gaze detector incorporated into thevirtual sleep assistant hardware that detects the user closing his orher eyes. In some cases, the system 100 may turn off the virtual sleepassistant 218 upon detecting the closing of the person's eyes, or turnoff only the visual display when the eyes of the user are closed.

In yet another embodiment, the physiological feedback data may be usedto detect a state of full sleep, or a state sufficiently close to fullsleep, and turn off the sleep assistant 218 after certain physiologicalconditions have been met. As an example, the system 100 can detect,based on the physiological signals, whether a person has fallen asleepor wishes to discontinue using the system 100 as follows. When theperson begins using the system 100, they begin by consciously slowingtheir breathing rate, and the system 100 detects a low breathing rate.However, when people fall asleep, they lose the voluntary control oftheir own breathing. Therefore, once the person falls asleep, theirbreathing rate returns to “normal,” and the system 100 detects anincrease in the breathing rate relative to the previously-slowedbreathing rate (e.g., the breathing rate voluntarily slowed by the userperforming a relaxation technique while conscious). The system 100 canthus turn off the sleep assistant application 218 when the system 100detects a normal breathing rate for a certain period of time (e.g. whenthe person falls asleep) after having previously detected a lowbreathing rate for a certain period of time. A return to a normalbreathing rate could also mean that the user has discontinued thevoluntary slow breathing the person does not want use the deviceanymore. In this case as well, the system 100 can turn off the sleepassistant application 218 in response to the return to a normalbreathing rate. In this way, the sleep assistant 218 is configured toguide individuals toward sleep, starting from a conscious level (whichtypically occurs at the beginning of the night, when the person is stillawake), through intermediate stages in which users use the VRbiofeedback system, up to the point at which when they fall sleep(unconsciousness). During the intermediate stages, the system 100automatically adjusts the immersive virtual environment (by increasingthe sense of presence or degree of immersiveness) so that the userprogressively feels that the (unreal) virtual environment is actuallytheir real (physical) environment. As the user's sense of presence inthe virtual environment increases, the user's mind is distracted fromaspects of their real environment that normally disrupt sleep (such asphysical features of the room, emotional connections with the physicalenvironment, and thoughts of worry and rumination).

If the virtual reality sleep promotion is to be continued, the system100 determines whether the stage of the virtual environment (and/or anaspect of the physical environment, e.g., a setting of a smart device266) is to be changed, at block 426. The determination as to whether tochange the virtual and/or physical environment can be made in the samemanner as described in block 416. That is, the system maps the newphysiological parameter values determined at block 422 to a stage of thevirtual and/or physical environment (using, e.g., one or more mappingfunctions 234). The new parameter values may relate to the stage(s) ofthe virtual and/or physical environments that are currently beingpresented, in which no change is made to the virtual and/or physicalenvironment, and the system 100 returns to block 418 and continuespresenting the same stage of the virtual and/or physical environment(s)as was done previously. If the new parameter values relate to adifferent stage of the virtual and/or physical environment(s) than thestage that is currently being presented, the system 100 returns to block416 and proceeds to determine the specifications for and present the newstage. In other embodiments, the decision at block 426 may be performedby comparing the old physiological parameter value determined at block414 to the new physiological parameter determined at block 422. If theold physiological parameter value and the new physiological parametervalue are the same or within an acceptable range of difference, thesystem 100 continues presenting the current stage of the virtual and/orphysical environment(s), and the process of monitoring physiologicalsignals continues. If the old physiological parameter value and the newphysiological parameter value are different or outside an acceptablerange of difference, then the stage of the virtual and/or physicalenvironment(s) is updated to correspond to the new physiologicalparameters, and the process of monitoring physiological signalscontinues.

Referring now to FIGS. 5 and 6, illustrative plots of sensor data areshown, which compare the use of an inertial measurement unit (IMU) tomeasure respiration rate to the results obtained using a piezorespiratory effort band (“p-band”), which is the conventional “goldstandard” method used to capture respiration data duringpolysomnographic sleep recordings. In FIG. 5, the plot 500 shows lowfrequency breathing of a person during controlled feedback relaxationinduced by the sleep assistant 218, but prior to sleep. Graph line 510shows the breathing frequency measured by the p-band over time. Graphlines 512, 514, 516, 518, 520, and 522 show the six outputs of an IMUmeasuring the respiration rate over time. Typically, an IMU comprises athree-axis accelerometer and a three-axis gyroscope. Breathing frequencyis estimated by analyzing accelerometer data and combining it withgyroscope data, if available. A smoothing function (such as that whichmay be provided by a smart phone application) may be used to delay thefeedback response and thereby compensate for breathing changes thatresult from the user's body movements or other artifacts.

Graph line 524 shows the breathing frequency (in Hertz) of a person asmeasured by the p-band, and graph line 526 shows the breathing frequencyof a person measured using the IMU. Both the p-band and the IMUmeasurement techniques exhibit similar performance. The plot 600, foundin FIG. 6, is nearly identical to the graph 500, found in FIG. 5, exceptthat the plot 600 is a measurement of breathing frequency of a personduring a period of sleep. Graph lines 610 and 624 relate to the p-bandmeasurements, and graph lines 612, 614, 616, 618, 620, 622, and 626relate to the IMU measurements. Again, the p-band and the IMU exhibitsimilar performance.

It should be noted that the breathing rate can be affected by artifactssuch as body movements, which usually occur at the sleep onset (e.g.,people turning over or changing position, etc.) In some embodiments, inorder to avoid rapid changes in the feedback output due to bodymovements, the system 100 executes a function (e.g., a smoothingfunction) to correct the artifact before providing the feedback to thesleep assistant 218.

Referring now to FIGS. 7-9, exemplary plots of test results obtainedduring trials illustrate the effectiveness of an embodiment of the sleepassistant 218 in comparison to a baseline night in which the sleepassistant 218 was not used. FIG. 7 shows that a lower heart rate isestablished during an initial period of low breathing rate using thesleep assistant 218 and the lower heart rate is maintained after theonset of sleep. FIG. 8 shows that in the same trial, the lower heartrate was established with the sleep assistant 218 prior to sleep andmaintained during both rapid eye movement (REM) and non-rapid eyemovement (NREM) periods of sleep, across the whole night. FIG. 9compares a measure of sleep quality for a baseline night in which thesleep assistant 218 was not used and a night in which the sleepassistant 218 was used, and shows that sleep quality improved with theuse of the sleep assistant 218.

Additional Examples

Illustrative examples of the technologies disclosed herein are providedbelow. An embodiment of the technologies may include any one or more,and any combination of, the examples described below.

In an example 1, a method for promoting sleep includes, with abiofeedback virtual reality system: monitoring a physiological signalreceived from a sensor over time; presenting an immersive virtualenvironment with a virtual reality device, the immersive virtualenvironment comprising a display of visual elements designed to promotesleep; detecting a change in the physiological signal, and in responseto the detected change in the physiological signal: applying biofeedbacktechnology to determine an adjustment to the immersive virtualenvironment, wherein the adjustment is to change the display of visualelements; and presenting the adjustment to the immersive virtualenvironment with the virtual reality device.

In an example 2, the method includes the subject matter of example 1 andincludes receiving the physiological signal at a mobile or wearablesensing and computing device, and determining one or more physiologicalparameters based on the physiological signal. In an example 3, themethod includes the subject matter of example 1 or example 2 andincludes presenting the immersive virtual environment is in response toa user actively attempting to control a physiological parameter beingsensed by the sensor. In an example 4, the method includes the subjectmatter of any of the preceding examples and includes selecting theimmersive virtual environment from a plurality of stored immersivevirtual environments based on the physiological signals and/or usercustomization data. In an example 5, the method includes the subjectmatter of any of the preceding examples and includes determining usercustomization data and determining the adjustment to the immersivevirtual environment based on the user customization data. In an example6, the method includes the subject matter of any of the precedingexamples and includes, wherein the immersive virtual environmentcomprises an audio soundtrack, applying biofeedback technology todetermine an adjustment to the audio soundtrack and applying theadjustment to the audio soundtrack with the virtual reality device. Inan example 7, the method includes the subject matter of any of thepreceding examples and includes determining a mapping defining arelationship between physiological signals and elements of the immersivevirtual environment, wherein the mapping is defined to promote sleep,and using the mapping to determine the adjustment to the immersivevirtual environment. In an example 8, the method includes the subjectmatter of any of the preceding examples and includes storing datarelating to adjustments made to the immersive virtual environment overtime and physiological signals monitored after the adjustments have beenmade, applying an artificial intelligence or machine learning techniqueto the stored data to algorithmically learn a modification to themapping; and updating the mapping to include the learned modification.

In an example 9, the method includes the subject matter of any of thepreceding examples and includes detecting a sleep state based on themonitoring of the physiological signal and turning off the display ofvisual elements in response to the sleep state. In an example 10, themethod includes the subject matter of any of the preceding examples andincludes, wherein the physiological signal represents a respiration rateor a heart rate or muscle activity, the monitoring detects a change inthe respiration rate, heart rate, or muscle activity, in response to thechange in the respiration rate, heart rate or muscle activity, changinga speed, quantity, density, frequency, color, brightness, contrast,direction, depth, focus, point of view, and/or complexity of one or moreof the visual elements in the presentation of the immersive virtualenvironment. In an example 11, the method includes the subject matter ofany of the preceding examples and includes, wherein the immersivevirtual environment further comprises an audio soundtrack, changing thevolume, content, speed, complexity, and/or intensity of the audiosoundtrack in response to the change in the respiration rate or heartrate. In an example 12, the method includes the subject matter of any ofthe preceding examples and includes, wherein the physiological signalrepresents a respiration rate or a heart rate, the monitoring detects adecrease in the respiration rate or heart rate, and the methodcomprises, in response to the decrease in the respiration rate or heartrate, decreasing speed, and increasing quantity, density and/orfrequency of one or more of the visual elements in the presentation ofthe immersive virtual environment. In an example 13, the method includesthe subject matter of any of the preceding examples and includes,wherein the immersive virtual environment further comprises an audiosoundtrack, increasing the volume or degree of surround sound at whichthe audio soundtrack is played in response to the decrease in therespiration rate or heart rate. In an example 14, the method includesthe subject matter of any of the preceding examples and includes,wherein the physiological signal represents a respiration rate or aheart rate or a rate of muscle activity, the monitoring detects anincrease in the respiration rate or heart rate or muscle activity, inresponse to the increase in the respiration rate or heart rate or muscleactivity, increasing speed, and decreasing quantity, density, and/orfrequency of one or more of the visual elements in the presentation ofthe immersive virtual environment.

In an example 15, the method includes the subject matter of any of thepreceding examples and includes decreasing the volume at which the audiosoundtrack is played in response to the increase in the respiration rateor heart rate. In an example 16, the method includes the subject matterof any of the preceding examples and includes determining a value of aphysiological parameter based on the physiological signal, wherein thephysiological parameter has a range of possible values, the immersivevirtual environment comprises a plurality of visual stages, each of thevisual stages comprises a different arrangement of visual elements, eachof the visual stages corresponds to a different subset of the range ofpossible values of the physiological parameter, determining theadjustment comprises selecting a visual stage corresponding to thedetermined value of the physiological parameter, and presenting theadjustment comprises presenting the selected visual stage. In an example17, the method includes the subject matter of any of the precedingexamples and includes, wherein the immersive virtual environmentcomprises a plurality of audio stages, each of the audio stagescomprises a different arrangement of audio elements, each of the audiostages corresponds to a different subset of the range of possible valuesof the physiological parameter, determining the adjustment comprisesselecting an audio stage corresponding to the determined value of thephysiological parameter, and presenting the adjustment comprisespresenting the selected audio stage. In an example 18, the methodincludes the subject matter of any of the preceding examples andincludes determining, a value of a physiological parameter from thephysiological signal, wherein the physiological parameter comprises arespiration rate, a heart rate, an electroencephalography (EEG)measurement, a measure of muscle activity, and/or a human bodytemperature, and determining the adjustment to the immersive virtualenvironment based on the value of the physiological parameter. In anexample 19, the method includes the subject matter of any of thepreceding examples and includes, wherein the immersive virtualenvironment further comprises an audio soundtrack, determining a visualadjustment to adjust the display of visual elements and determining anaudio adjustment to adjust the audio soundtrack. In an example 20, themethod includes the subject matter of any of the preceding examples andincludes determining the visual adjustment independently of thedetermining of the audio adjustment. In an example 21, the methodincludes the subject matter of any of the preceding examples andincludes, wherein the immersive virtual environment comprises aplurality of different sensory stimuli, independently adjusting each ofthe different sensory stimuli in response to the change in thephysiological signal.

An example 22 includes a biofeedback virtual reality system forpromoting sleep, the biofeedback virtual reality system including: asensor to detect a physiological signal; a mobile or wearable computingdevice to: receive the physiological signal; determine a value of aphysiological parameter based on the physiological signal; map the valueof the physiological parameter to a stage of an immersive virtualenvironment of a plurality of stored immersive virtual environments,each of the stored immersive virtual environments comprising asuccession of stages designed to promote sleep, each of the stagescomprising a different arrangement of sensory stimuli; and a virtualreality device in communication with the mobile or wearable computingdevice, the virtual reality device to present the stage of the immersivevirtual environment; wherein the mobile or wearable computing device isto determine a new value of the physiological parameter and map the newvalue of the physiological parameter to a new stage of the immersivevirtual environment; and wherein the virtual reality device is topresent the new stage of the immersive virtual environment in responseto the new value of the physiological parameter.

In an example 23, the system includes the subject matter of example 22,wherein the mobile or wearable computing device comprises a smartphone,a tablet computer, an attachable/detachable device, a smart watch, smartglasses, a smart wristband, smart jewelry, and/or smart apparel. In anexample 24, the system includes the subject matter of example 22 orexample 23, wherein at least two of the mobile or wearable computingdevice, the virtual reality device, and the sensor are embodied as aunitary device. In an example 25, the system includes the subject matterof any of examples 22-24, wherein the mobile or wearable computingdevice receives the physiological signal through wireless communicationand/or the mobile or wearable computing device communicates with thevirtual reality device through wireless communication. In an example 26,the system includes the subject matter of any of examples 22-25, whereinthe sensor comprises a motion sensor, and wherein the mobile or wearablecomputing device determines a respiration rate from the output of themotion sensor. In an example 27, the system includes the subject matterof any of examples 22-26, wherein the mobile or wearable computingdevice comprises a positioner to position the mobile or wearablecomputing device to detect human body motion indicating breathing. In anexample 28, the system includes the subject matter of any of examples22-27, wherein the mobile or wearable computing device is to receive aplurality of different physiological signals, determine a value of eachof a plurality of different physiological parameters based on theplurality of different physiological signals, and determine a stage ofthe immersive virtual environment based on the values of the differentphysiological parameters. In an example 29, the system includes thesubject matter of any of examples 22-28, wherein the immersive virtualenvironment comprises an arrangement of visual elements including anavatar that interacts with the immersive virtual environment in responseto the physiological signal. In an example 30, the system includes thesubject matter of any of examples 22-29, comprising a gaze detector incommunication with the mobile or wearable computing device, wherein themobile or wearable computing device is to manipulate the immersivevirtual environment in response to output of the gaze detector. In anexample 31, the system includes the subject matter of any of examples22-30, wherein the virtual reality device comprises virtual realityeyewear and headphones. In an example 32, the system includes thesubject matter of any of examples 22-31, wherein the virtual realitydevice comprises high-definition video glasses, a non-rigid sleep mask,a television, a projector to project a display of visual elements onto awall or ceiling, and/or one or more remote speakers.

An example 33 includes a biofeedback virtual reality sleep assistantembodied in one or more computer accessible media, the biofeedbackvirtual reality sleep assistant including: a physiological signalprocessor to receive one or more physiological signals from one or moresensing devices; a physiological signal processing module to monitor oneor more physiological parameters from the one or more physiologicalsignals over time, each of the physiological parameters having a rangeof possible values, and to determine a value of each of thephysiological parameters at a plurality of different instances in time;a physiological parameter mapping module to map the values of the one ormore physiological parameters at an instance in time to a stage of animmersive virtual environment selected from a plurality of storedimmersive virtual environments, each of the immersive virtualenvironments comprising at least a visual display and an audiosoundtrack, each of the visual display and the audio soundtrack having aplurality of successive stages designed to promote sleep; and animmersive environment control module to present the stage of theselected immersive virtual environment by one or more virtual realitydevices; wherein the physiological signal processing module is to detectchanges in the values of the one or more physiological parameters overtime; and wherein the physiological parameter mapping module is tochange the stage of the selected immersive virtual environment inresponse to the changes in the values of the one or more physiologicalparameters.

In an example 34, the sleep assistant includes the subject matter ofclaim 33, wherein the physiological parameter mapping module map thevalues of the one or more physiological parameters to a stage of animmersive virtual environment by executing a continuous mapping functionor by accessing a lookup table. In an example 35, the sleep assistantincludes the subject matter of claim 33, wherein the physiologicalparameter mapping module is to map the values of the one or morephysiological parameters to a stage of the visual display and separatelymap the values of the one or more physiological parameters to a stage ofthe audio soundtrack. In an example 36, the sleep assistant includes thesubject matter of claim 33, wherein the immersive environment controlmodule is to construct the selected immersive virtual environment inreal time by adding, deleting, or changing elements of the visualdisplay and/or the audio soundtrack based on the values of the one ormore physiological parameters. In an example 37, the sleep assistantincludes the subject matter of claim 33, wherein the immersiveenvironment control module is to communicate with a smart device tocontrol an aspect of a physical environment in response to changes inthe values of the one or more physiological parameters over time.

An example 38 includes an article of manufacture including, embodied inone or more computer accessible storage media: an immersive virtualenvironment comprising a display of visual elements and an audiosoundtrack, wherein the display and the audio soundtrack each have aplurality of stages that are coordinated with different values of atleast one physiological parameter.

General Considerations

In the foregoing description, numerous specific details, examples, andscenarios are set forth in order to provide a more thoroughunderstanding of the present disclosure. It will be appreciated,however, that embodiments of the disclosure may be practiced withoutsuch specific details. Further, such examples and scenarios are providedfor illustration, and are not intended to limit the disclosure in anyway. Those of ordinary skill in the art, with the included descriptions,should be able to implement appropriate functionality without undueexperimentation.

References in the specification to “an embodiment,” etc., indicate thatthe embodiment described may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Such phrases are notnecessarily referring to the same embodiment. Further, when a particularfeature, structure, or characteristic is described in connection with anembodiment, it is believed to be within the knowledge of one skilled inthe art to effect such feature, structure, or characteristic inconnection with other embodiments whether or not explicitly indicated.

Embodiments in accordance with the disclosure may be implemented inhardware, firmware, software, or any combination thereof. Embodimentsmay also be implemented as instructions stored using one or moremachine-readable media, which may be read and executed by one or moreprocessors. A machine-readable medium may include any mechanism forstoring or transmitting information in a form readable by a machine(e.g., a computing device or a “virtual machine” running on one or morecomputing devices). For example, a machine-readable medium may includeany suitable form of volatile or non-volatile memory.

Modules, data structures, and the like defined herein are defined assuch for ease of discussion, and are not intended to imply that anyspecific implementation details are required. For example, any of thedescribed modules and/or data structures may be combined or divided intosub-modules, sub-processes or other units of computer code or data asmay be required by a particular design or implementation.

In the drawings, specific arrangements or orderings of schematicelements may be shown for ease of description. However, the specificordering or arrangement of such elements is not meant to imply that aparticular order or sequence of processing, or separation of processes,is required in all embodiments. In general, schematic elements used torepresent instruction blocks or modules may be implemented using anysuitable form of machine-readable instruction, and each such instructionmay be implemented using any suitable programming language, library,application-programming interface (API), and/or other softwaredevelopment tools or frameworks. Similarly, schematic elements used torepresent data or information may be implemented using any suitableelectronic arrangement or data structure. Further, some connections,relationships or associations between elements may be simplified or notshown in the drawings so as not to obscure the disclosure.

This disclosure is to be considered as exemplary and not restrictive incharacter, and all changes and modifications that come within the spiritof the disclosure are desired to be protected.

1. A method for promoting sleep, the method comprising, with abiofeedback virtual reality system: monitoring a physiological signalreceived from a sensor over time; presenting an immersive virtualenvironment with a virtual reality device, the immersive virtualenvironment comprising a display of visual elements designed to promotesleep; detecting a change in the physiological signal, and in responseto the detected change in the physiological signal: applying biofeedbacktechnology to determine an adjustment to the immersive virtualenvironment, wherein the adjustment is to change the display of visualelements; and presenting the adjustment to the immersive virtualenvironment with the virtual reality device.
 2. The method of claim 1,comprising receiving the physiological signal at a mobile or wearablesensing and computing device, and determining one or more physiologicalparameters based on the physiological signal.
 3. The method of claim 1,where the presenting of the immersive virtual environment is in responseto a user actively attempting to control a physiological parameter beingsensed by the sensor.
 4. The method of claim 1, comprising selecting theimmersive virtual environment from a plurality of stored immersivevirtual environments based on the physiological signals and/or usercustomization data.
 5. The method of claim 1, comprising determininguser customization data and determining the adjustment to the immersivevirtual environment based on the user customization data.
 6. The methodof claim 1, wherein the immersive virtual environment comprises an audiosoundtrack, and the method comprises applying biofeedback technology todetermine an adjustment to the audio soundtrack and applying theadjustment to the audio soundtrack with the virtual reality device. 7.The method of claim 1, comprising determining a mapping defining arelationship between physiological signals and elements of the immersivevirtual environment, wherein the mapping is defined to promote sleep,and using the mapping to determine the adjustment to the immersivevirtual environment.
 8. The method of claim 7, comprising storing datarelating to adjustments made to the immersive virtual environment overtime and physiological signals monitored after the adjustments have beenmade, applying an artificial intelligence or machine learning techniqueto the stored data to algorithmically learn a modification to themapping; and updating the mapping to include the learned modification.9. The method of claim 1, comprising detecting a sleep state based onthe monitoring of the physiological signal and turning off the displayof visual elements in response to the sleep state.
 10. The method ofclaim 1, wherein the physiological signal represents a respiration rateor a heart rate or muscle activity, the monitoring detects a change inthe respiration rate, heart rate, or muscle activity and the methodcomprises, in response to the change in the respiration rate, heart rateor muscle activity, changing a speed, quantity, density, frequency,color, brightness, contrast, direction, depth, focus, point of view,and/or complexity of one or more of the visual elements in thepresentation of the immersive virtual environment.
 11. The method ofclaim 10, wherein the immersive virtual environment further comprises anaudio soundtrack, and the method comprises changing the volume, content,speed, complexity, and/or intensity of the audio soundtrack in responseto the change in the respiration rate or heart rate.
 12. The method ofclaim 1, wherein the physiological signal represents a respiration rateor a heart rate, the monitoring detects a decrease in the respirationrate or heart rate, and the method comprises, in response to thedecrease in the respiration rate or heart rate, decreasing speed, andincreasing quantity, density and/or frequency of one or more of thevisual elements in the presentation of the immersive virtualenvironment.
 13. The method of claim 12, wherein the immersive virtualenvironment further comprises an audio soundtrack, and the methodcomprises increasing the volume or degree of surround sound at which theaudio soundtrack is played in response to the decrease in therespiration rate or heart rate.
 14. The method of claim 13, wherein thephysiological signal represents a respiration rate or a heart rate or arate of muscle activity, the monitoring detects a change in therespiration rate or heart rate or muscle activity, and the methodcomprises, in response to the change in the respiration rate or heartrate or muscle activity, changing speed, quantity, density, and/orfrequency of one or more of the visual elements in the presentation ofthe immersive virtual environment.
 15. The method of claim 14,comprising changing the volume at which the audio soundtrack is playedin response to the change in the respiration rate or heart rate.
 16. Themethod of claim 1, comprising determining a value of a physiologicalparameter based on the physiological signal, wherein the physiologicalparameter has a range of possible values, the immersive virtualenvironment comprises a plurality of visual stages, each of the visualstages comprises a different arrangement of visual elements, each of thevisual stages corresponds to a different subset of the range of possiblevalues of the physiological parameter, determining the adjustmentcomprises selecting a visual stage corresponding to the determined valueof the physiological parameter, and presenting the adjustment comprisespresenting the selected visual stage.
 17. The method of claim 1, whereinthe immersive virtual environment comprises a plurality of audio stages,each of the audio stages comprises a different arrangement of audioelements, each of the audio stages corresponds to a different subset ofthe range of possible values of the physiological parameter, determiningthe adjustment comprises selecting an audio stage corresponding to thedetermined value of the physiological parameter, and presenting theadjustment comprises presenting the selected audio stage.
 18. The methodof claim 1, comprising, determining, a value of a physiologicalparameter from the physiological signal, wherein the physiologicalparameter comprises a respiration rate, a heart rate, anelectroencephalography (EEG) measurement, a measure of muscle activity,and/or a human body temperature, and determining the adjustment to theimmersive virtual environment based on the value of the physiologicalparameter.
 19. The method of claim 1, wherein the immersive virtualenvironment further comprises an audio soundtrack, and the methodcomprises determining a visual adjustment to adjust the display ofvisual elements and determining an audio adjustment to adjust the audiosoundtrack.
 20. The method of claim 19 comprising determining the visualadjustment independently of the determining of the audio adjustment. 21.The method of claim 1, wherein the immersive virtual environmentcomprises a plurality of different sensory stimuli, and the methodcomprises independently adjusting each of the different sensory stimuliin response to the change in the physiological signal.
 22. A biofeedbackvirtual reality system for promoting sleep, the biofeedback virtualreality system comprising: a sensor to detect a physiological signal; amobile or wearable computing device to: receive the physiologicalsignal; determine a value of a physiological parameter based on thephysiological signal; map the value of the physiological parameter to astage of a succession of stages designed to promote sleep, each of thestages comprising a different arrangement of sensory stimuli including aplurality of visual display elements; and a non-rigid personal displaydevice in communication with the mobile or wearable computing device,the non-rigid personal display device to present the stage; wherein themobile or wearable computing device is to determine a new value of thephysiological parameter and map the new value of the physiologicalparameter to a new stage of the succession of stages; and wherein thenon-rigid personal display device is to present the new stage inresponse to the new value of the physiological parameter.
 23. The systemof claim 22, wherein the mobile or wearable computing device comprises asmartphone, a tablet computer, an attachable/detachable device, a smartwatch, smart glasses, a smart wristband, smart jewelry, and/or smartapparel.
 24. The system of claim 22, wherein at least two of the mobileor wearable computing device, the non-rigid personal display device, andthe sensor are embodied as a unitary device.
 25. The system of claim 22,wherein the mobile or wearable computing device receives thephysiological signal through wireless communication and/or the mobile orwearable computing device communicates with the non-rigid personaldisplay device through wireless communication.
 26. The system of claim22, wherein the sensor comprises a motion sensor, and wherein the mobileor wearable computing device determines a respiration rate from theoutput of the motion sensor.
 27. The system of claim 22, wherein themobile or wearable computing device comprises a positioner to positionthe mobile or wearable computing device to detect human body motionindicating breathing.
 28. The system of claim 22, wherein the mobile orwearable computing device is to receive a plurality of differentphysiological signals, determine a value of each of a plurality ofdifferent physiological parameters based on the plurality of differentphysiological signals, and determine a stage of the succession of stagesbased on the values of the different physiological parameters.
 29. Thesystem of claim 22, wherein the stage comprises an arrangement of visualelements including an avatar that interacts with the arrangement ofvisual elements in response to the physiological signal.
 30. The systemof claim 22, comprising a gaze detector in communication with the mobileor wearable computing device, wherein the mobile or wearable computingdevice is to select a stage of the succession of stages in response tooutput of the gaze detector.
 31. The system of claim 22, furthercomprising, wherein the non-rigid personal display device comprisesvirtual reality eyewear and headphones.
 32. The system of claim 22,wherein the non-rigid personal display device comprises high-definitionvideo glasses, a non-rigid sleep mask, a television, a projector toproject a display of visual elements onto a wall or ceiling, and/or oneor more remote speakers.
 33. A biofeedback virtual reality sleepassistant embodied in one or more computer accessible media, thebiofeedback virtual reality sleep assistant comprising: a physiologicalsignal processor to receive one or more physiological signals from oneor more sensing devices; a physiological signal processing module tomonitor one or more physiological parameters from the one or morephysiological signals over time, each of the physiological parametershaving a range of possible values, and to determine a value of each ofthe physiological parameters at a plurality of different instances intime; a physiological parameter mapping module to map the values of theone or more physiological parameters at an instance in time to a stageof an immersive virtual environment selected from a plurality of storedimmersive virtual environments, each of the immersive virtualenvironments comprising at least a visual display and an audiosoundtrack, each of the visual display and the audio soundtrack having aplurality of successive stages designed to promote sleep; and animmersive environment control module to present the stage of theselected immersive virtual environment by one or more virtual realitydevices; wherein the physiological signal processing module is to detectchanges in the values of the one or more physiological parameters overtime; and wherein the physiological parameter mapping module is tochange the stage of the selected immersive virtual environment inresponse to the changes in the values of the one or more physiologicalparameters.
 34. The sleep assistant of claim 33, wherein thephysiological parameter mapping module map the values of the one or morephysiological parameters to a stage of an immersive virtual environmentby executing a continuous mapping function or by accessing a lookuptable.
 35. The sleep assistant of claim 33, wherein the physiologicalparameter mapping module is to map the values of the one or morephysiological parameters to a stage of the visual display and separatelymap the values of the one or more physiological parameters to a stage ofthe audio soundtrack.
 36. The sleep assistant of claim 33, wherein theimmersive environment control module is to construct the selectedimmersive virtual environment in real time by adding, deleting, orchanging elements of the visual display and/or the audio soundtrackbased on the values of the one or more physiological parameters.
 37. Thesleep assistant of claim 33, wherein the immersive environment controlmodule is to communicate with a smart device to control an aspect of aphysical environment in response to changes in the values of the one ormore physiological parameters over time.
 38. An article of manufacturecomprising, embodied in one or more computer accessible storage media:an immersive virtual environment comprising a display of visual elementsand an audio soundtrack, wherein the display and the audio soundtrackeach have a plurality of stages that are coordinated with differentvalues of at least one physiological parameter.
 39. The system of claim22, wherein the succession of stages is stored as an immersive virtualenvironment of a plurality of stored immersive virtual environments, andthe mobile or wearable computing device is to select the immersivevirtual environment from the plurality of stored immersive virtualenvironments.